Ch.10 Vascular Physiology Flashcards
1
Q
blood reconditioning occurs
A
constantly
2
Q
purpose of blood recoditioning
A
- adjust blood flow to maintain homeostasis
3
Q
what are the reconditioning organs
A
- digestive organs
- kidneys
- skin
4
Q
what is the purpose of reconditioning organs
A
- receive more blood then need so has the ability to redistribute it
5
Q
non reconditioning organs include
A
- brain
- skeletal musclesw
6
Q
what is the purpose of non reconditioning organs
A
- increase blood supple to achieve homeostasis
7
Q
flow rate formula
A
FR=P/R
8
Q
what is the pressure gradient
A
- the pressure difference between the beginning and end of the vessel
9
Q
where does blow flow in the pressure area
A
- moves from an area of high concentration to low concentration
- moves down the pressure gradient
10
Q
resistance is
A
the measure of opposition to the blood flow
11
Q
increased resistance ________ flow rate
A
decreases
12
Q
what are the three factors that influence resistance
A
- vessel viscosity
- vesssel lenght
- vessel radius
13
Q
what is the MAJOR determinate of resistance
A
- vessel radius
14
Q
how does vessel radius effect resistance
A
decreased radius = increased resistance
15
Q
how does vessel lenght effect resistance
A
longer vessel = more surface area = increased resistance
16
Q
how is vessel viscosity determined
A
- by the number of RBC’s
17
Q
how does vessel viscosity effect resistance
A
increased viscosity = greater resistance
18
Q
arterial blood pressure =
A
constant
19
Q
arteries are also know as
A
rapid transit pathways
20
Q
resistance in the arteries is
A
little
21
Q
arteries act as
A
pressure reserviours
22
Q
why are arteries known as pressure reservoirs
A
- they are the driving force for blood when the heart is relaxing
23
Q
Pulse pressure formula
A
PP= SBP - DBP
24
Q
what is normal pulse pressure
A
40 mm HG
25
what is pulse pressure
- pressure difference between systolic and diastolic pressure
26
systolic pressure
- maximum pressure excreted in the arteries
- when the ventricles contracts
27
what is normal systolic pressure
120
28
diastolic pressure
- minimum pressure in the arteries
- ventricles relaxes
29
what is normal diastolic pressure
80
30
Mean arterial pressure formula
MAP = DP + 1/3 SP
31
what is normal MAP
93
32
what is mean arterial pressure
- the average pressure driving blood forward into tissues throughout the cardiac system
33
MAP must be high enough to
ensure sufficent driving pressure
34
MAP must not be too high because
it will make excess work for the heart and ruture the capillaries
35
arterioles are
major resitance vessels
36
why are arterioles known as major resitance vessels
- because they vasoconstrict
37
arterioles makeup
- highly musclular
- contain very little elastic tissue
38
Purpose of arterioles
- adjust to recondition organs
- help reguate MAP
39
vasoconstriction
- narrowing of the vessel wall
40
vasoconstriction effect on resistance
- increases resistance
41
vasodilation
- relaxation
- enlargement of the circumfrance of the vessel
42
vasodialtion effect on resistance
- decreases resistance
43
increased myogenic activity causes
| myogenic activity = ability of blood vessels to constrict
vasoconstriction
44
decreases oxygen causes
vasodilation
45
increases carbon dioxide casues
vasodialation
46
increased endothelin causes
vasoconstriction
47
decreased myogenic activity causes
vasodilation
48
increased oxegen casues
vasoconstriction
49
decreased carbon dioxide casues
vasoconstriction
50
decreased sypathetic stimulation causes
vasodialtion
51
increased heat causes
vasodilation
52
decreased heat causes
vasoconstriction
53
increased sympathetic stimulation causes
vasoconstriction
54
increased sympathetic stimulation is caused by
- an increase is vasopressin
- an increase in angiotension II
55
decreased sypathetic stimulation is caused by
- increased histamine
56
types of intrinsic controls
- chemical influences
- physical influences
57
what are intrinsic controls
- changes within a tissue / organ
- alters radius of a vessel by altering smooth muscle
58
What are chemical influences
- local metabolic changes
- histamine release
59
what are physical influences
- hot / cold
- chemical responce to shear stress
- myogenic responce to stretch
60
extrinsic controls are important in
blood pressure regulation
61
extrinsic controls examples
- neural inputs (hormones)
62
Capillaries are known as
"exchange vessels"
63
why are capillaries known as exchanged vessels
-they have maximized surface area and maximized diffusion
- slow velocity
64
what does slow velocity do
- allow enough time for exchange
65
Velocity of blood flow is _____________ to total cross sectional area
inversly proportional
66
Hwo are substances exchanged through cappilaries
- diffusion
- bulk flow
67
the lymphatic system provides
an excessory route by which fluid can be returned from the interstial fluid to the blood
68
oedema is also known as
the swelling of the tissues
69
when does oedema occur
when too much intersticial fluid accumulates
70
causes of oedema
- decreases concentration of plasma proteins (kidney / liver disease, loss of plasma proteins burned from the surface)
- increased permulability of cappillary wall (allergic reactions)
71
veins are also known as
blood reserviours
72
makeup of veins
- little restance
- highly densiable
- less cross sectional area (walls appear thin and collapsed)
- little smooth muscle
- little elasticity
73
Main determinate of MAP
- cardiac output
- total peripheral resistance
74
MAP formula #2
MAP = CO x TPR
75
sympathetic stimulation activates
a1 - adrenoceptors
76
Parasympathic stimulation effect on blood pressure
decreases
77
hypovolmic shock effect on CO
decreases
78
Hypovolmic shock is
low volume shock
79
Hypovolmic shock causes
- sever haemorrhage
- excessive vommiting
- diarrhoea
- urinary losses
80
cardiogenic shock is
heart produced shock
81
cardiogenic shock is caused by
- weekend heart
82
cardiogenic shock effect on cardiac output
decreased CO
83
vasogenic shock is
vessel produced shock
84
vasogenic shock effect on total peripheral resistance
decreases
85
vasogenic shock is caused by
- septic shock
- anaphylactic shock
86
effect of septic shock
vasodilator released from bacteria
87
effect of anaphylatic shock
- increased histamine ---> vasodialtion
88
neurogenic shock is
nerve produced shock
89
neurogenic shock effect on TPR
decreases
90
Effect of Neurogenic shock
decreased sympathic activity ---> decreased vascular tone ---> vasodialtion
